Bacteriological methods as add on tests to fine-needle aspiration cytology in diagnosis of tuberculous lymphadenitis: can they reduce the diagnostic dilemma?

Cytomorphological patterns and clinical features of presumptive tubercular lymphadenitis patients and their comparison with bacteriological detection methods: a cross-sectional study

INTRODUCTION

Tuberculous lymphadenitis (TBLN) is an infection of the lymph node caused by Mycobacterium tuberculosis. Histological diagnoses of presumptive patients are often accompanied by cytomorphological features. However, the sensitivities of these features are often precluded by the variable degrees of narrative similarities compared to other diagnostic modalities.

OBJECTIVE

The aim of this study was to investigate and compare the cytomorphological and clinical features of presumptive TBLN patients with bacteriological detection methods.

METHODS

A similar cohort of TBLN patients from our previous study who were enrolled prospectively from the ALERT Specialized Hospital, Addis Ababa, Ethiopia, was considered for this analysis. SPSS version 26 was used for data analysis. Descriptive analysis was conducted to characterize the study population using the independent variable and presented with frequency tables. The chi-square test was used to measure the association. A P-value of < 0.05 was considered statistically significant.

RESULTS

Using FNAC, 60/126 (47.6%) of the participants were reported to have features consistent with TB. Of the total FNAC-positive cases, many (30/60 and 27/60) showed pattern B (caseous necrosis only) and pattern C (epithelioid granuloma with caseous necrosis), respectively. Strong concordance was observed in Pattern A (abundant caseous necrosis with few epithelioid macrophages) followed by patterns B and C with GeneXpert and MGIT culture (P value < 0.001). Night sweats and alcohol intake were shown to correlate with positive cases as reported by FNAC (P value = 0.008 respectively), GeneXpert (P value = 0.02 & 0.001), and culture methods (P-value = < 0.001 & 0.002).

CONCLUSION

Cytomorphological features, particularly patterns A, B, and C, could be considered in the diagnosis of TBLN given their comparable outcomes with bacteriological detection methods. On another note, we recommend that due care and attention be given when treating TBLN patients based solely on clinical presentation, as these diagnostics may be prone to false results, leading to inappropriate administration of anti-TB drugs and other consequences.

Utility of Rapid On-Site Evaluation during Bronchoscopy in the Diagnosis of Pulmonary Tuberculosis

INTRODUCTION

The diagnostic value of rapid on-site evaluation (ROSE) in bronchoscopy for lung tumors has been widely researched. However, the diagnostic efficacy of ROSE for pulmonary tuberculosis (TB) has not been extensively assessed yet. This study aimed to examine the value of ROSE in diagnosing pulmonary TB during bronchoscopy, and the relationship between ROSE cytology patterns and acid-fast bacilli (AFB) smears and mycobacterial cultures.

METHODS

A retrospective study was conducted at a single respiratory endoscopy center, including 418 patients under clinical or radiological suspicion of having pulmonary TB who underwent bronchoscopy. In addition to the use of ROSE and definitive cytology, material obtained by aspiration/lavage or brushing was sent for AFB smear and mycobacterial culture. If histopathological examination was required, endobronchial biopsy, transbronchial lung biopsy, and transbronchial needle aspiration were performed at the discretion of the clinician. A composite reference standard (CRS) was used as the diagnostic gold standard for this study. The diagnosis obtained by ROSE was compared with the final diagnosis.

RESULTS

Of the 418 patients studied, 282 (67.5%) were diagnosed on the basis of bronchoscopic findings, as follows: pulmonary TB, in 238 (84.4%); non-TB, in 44 (15.6%). In 238 pulmonary TB patients, ROSE cytology showed granulomas without necrosis were observed in 107 cases, granulomas and necrosis in 51 cases, caseous necrosis only in 25 cases, and nonspecific inflammation in 55 cases. For the diagnosis of TB according to CRS, ROSE showed the sensitivity, specificity, positive predictive value, and negative predictive value were 76.9%, 68.2%, 92.9%, and 35.3%, respectively. The positivity rate for bacterial detection through acid-fast staining and culture during bronchoscopy was 51.7%. The cytological pattern showed a higher detection rate for bacteria in cases of necrosis.

DISCUSSION

The application of ROSE during bronchoscopy is a straightforward procedure that delivers an immediate and precise assessment regarding the adequacy of collected samples, enabling a preliminary diagnosis of pulmonary TB. ROSE has exhibited a higher sensitivity in detecting pulmonary TB compared to microbiological examinations. In addition, the cytological presentation of ROSE tends to show a higher positivity rate for microbiological testing in caseous necrosis. Therefore, samples with these characteristics should be prioritized for microbiological examination after on-site evaluation.

Bacteriologically confirmed extrapulmonary tuberculosis and the associated risk factors among extrapulmonary tuberculosis suspected patients in Ethiopia: A systematic review and meta-analysis

BACKGROUND

The actual burden of bacteriologically confirmed extrapulmonary tuberculosis (EPTB) and risk factors in Ethiopia is not well known due to the lack of a strong surveillance system in Ethiopia. Thus, this study was conducted to estimate the pooled prevalence of bacteriologically confirmed EPTB and the associated risk factors among persons suspected to have non-respiratory tuberculosis in Ethiopia.

METHODS

A systematic review and meta-analysis of published studies reporting the prevalence of EPTB from searched electronic databases; Science Direct, PubMed, and Google Scholar was estimated spread across the research periods, nationally, and in different areas, using a fixed-effects model. We used I2 to analyze heterogeneity in the reported prevalence of bacteriologically confirmed extrapulmonary tuberculosis.

RESULTS

After reviewing 938 research articles, 20 studies (19 cross-sectional and 1 retrospective) from 2003 to 2021 were included in the final analyses. The pooled prevalence of bacteriologically confirmed EPTB was 43% (95%CI; 0.34-0.52, I2 = 98.45%). The asymmetry of the funnel plot revealed the presence of publication bias. Specifically the pooled prevalence of bacteriologically confirmed EPTB based on smear microscopy, Xpert MTB/RIF assay, and culture were 22% (95%CI; 0.13-0.30, I2 = 98.56%), 39% (95%CI; 0.23-0.54, I2 = 98.73%) and 49% (95%CI; 0.41-0.57, I2 = 96.43%) respectively. In this study, a history of pulmonary tuberculosis (PTB) contact with PTB patients, contact with live animals, consumption of raw milk, HIV-positive, male, and lower monthly income, were found to be independently associated with bacteriologically confirmed EPTB.

CONCLUSION

Ethiopia has a high rate of bacteriologically confirmed EPTB. A history of previous PTB, being HIV-positive and having contact with PTB patients were the most reported risk factors for EPTB in the majority of studies. Strengthening laboratory services for EPTB diagnosis should be given priority to diagnose EPTB cases as early as possible.

Utility of Fine Needle Aspiration Cytology (FNAC) in the diagnosis of tuberculous lymphadenitis compared to GeneXpert in a tertiary health care center in Northern Odisha, India

BACKGROUND

Diagnosis of extrapulmonary tuberculosis including tuberculous lymphadenitis (TBLN) is challenging because of its atypical clinical presentation, paucibacillary nature of mycobacteria at the infected sites, variation in sensitivity of a test to specimens collected by different methods and from different infected tissues.

METHODS

In the present study, suspected individuals for lymph node tuberculosis irrespective of age were enrolled prospectively and specimens were collected aseptically by fine needle aspiration (FNA). After the implementation of exclusion criteria, FNA specimens from a total of 278 cases of suspected TBLN were evaluated for cytomorphology (FNAC), presence of acid-fast bacillus (AFB) in smear microscopy and specific detection of mycobacterial DNA in cartridge-based nucleic acid amplification test (CBNAAT).

RESULTS

The results showed high prevalence of Type II (59.71%), followed by Type I (34.53%) and Type III (5.75%) pattern in FNAC. Non-type II patterns were significantly high in regions outside of the head and neck region (P = 0.031; OR = 2.125) and had an increasing trend of their occurrences with progression of age. The most affected age group was between 16 and 30 years with female preponderance documented in individuals below 45 years, whereas male preponderance was observed in higher age group patients, majority of whom had infected lymph nodes outside of HAN region (P = 0.063, OR = 1.998). The results also showed high sensitivity of CBNAAT (83.04%) method followed by FNAC (72.17%) with AFB smear exhibiting the disappointing results (sensitivity of 10.86%) compared to the CRS. High percentage of positivity was observed in Type III (AFB:25% vs CBNAAT: 100%) followed by Type II (AFB:10.2 vs CBNAAT: 76.5), while low detection was observed from samples with Type I (AFB:4.2 vs CBNAAT: 50). Interestingly, CBNAAT detection of TB was shown to be unaffected by gender, age and site of infection.

CONCLUSION

The study suggests a possible contributary role of age and gender for cytomorphological pattern distribution of TBLN at various body parts. Although FNAC detected TB in 77.1% of cases which were identified positive by CBNAAT and/or AFB, it is being solely based on cytomorphology cannot be used alone as a reliable diagnostic method for TBLN detection. Further, the negative results in CBNAAT for FNAC positive cases may not necessarily be non-TB cases and must be evaluated by other diagnostic modalities. We recommend for both cytomorphological investigation and CBNNAT for the fine needle aspirates from suspected TBLN and subsequent treatment to reduce the disease burden.

Tuberculosis in the Head and Neck: Changing Trends and Age-Related Patterns

OBJECTIVE

To evaluate changing trends in patient collectives, age-related patterns of manifestation, and diagnostic pathways of patients with extrapulmonary head and neck tuberculosis (TB), and to provide strategies to fasten diagnosis in these patients.

STUDY DESIGN

Case control study.

METHODS

A 10-year retrospective analysis of 35 patients diagnosed with extrapulmonary TB in the head and neck at a tertiary university institution from 2009 to 2019, with special focus on the influence of the patient's age on consideration of TB and clinical patterns.

RESULTS

The vast majority of patients younger than 40 years had their origin in countries with high TB burden (P = .0003), and TB was considered very early as a differential diagnosis (P = .0068), while most patients older than 40 years were domestic citizens initially suspected for a malignancy, who more often had an underlying immunosuppressive condition (0.0472). Most frequent manifestations in both groups were the lymph nodes, larynx, and oropharynx. Surprisingly, no differences in the rates of open TB or history of TB infection in the family anamnesis were found.

CONCLUSION

The two groups of patients found most often are younger patients migrating from regions with high TB burden and elderly domestic patients suffering from immunosuppressive conditions, with the latter often being misdiagnosed as malignancies. TB remains an important but difficult differential diagnosis, due to the initially unspecific symptoms and the great variety in the presentation of manifestations in the head and neck.

LEVEL OF EVIDENCE

4 "case-control study" Laryngoscope, 2021.

Epidemiology and the diagnostic challenge of extra-pulmonary tuberculosis in a teaching hospital in Ethiopia

BACKGROUND

Ethiopia reported a high rate of extra-pulmonary tuberculosis (EPTB) and the cases are increasing since the last three decades. However, diagnostic evidence to initiate TB treatment among EPTB cases is not well known. Therefore, we described the epidemiology and assessed how EPTB is diagnosed in a teaching hospital in Ethiopia.

METHODS

We conducted a retrospective review among all adult EPTB cases diagnosed in Yekatit 12 Hospital Medical College from 2015 to 2019. Using a standardized data abstraction sheet, we collected data from patients' medical records on sociodemographic, sites, and laboratory diagnosis of EPTB cases.

RESULTS

Of the 965 total TB cases, 49.8%(481) had a recorded diagnosis of EPTB during the study period. The mean age of EPTB patients was 32.9 years (SD±13.9) and 50.7% were males. Tubercular lymphadenitis (40.3%), abdominal (23.4%), and pleural TB(13.5%) were the most common sites of EPTB involvement, followed in descending order by the genitourinary, skeletal, central nervous system, abscess, breast, and laryngeal TB. We found a histopathology finding consistent with EPTB in 59.1% of cases, Acid-fast bacilli positive in 1.5%, and the rest diagnosed on radiological grounds. In the majority of cases, more than one diagnostic method was used to diagnose EPTB cases.

CONCLUSIONS

Nearly half of TB patients had a recorded diagnosis of EPTB that comprise heterogeneous anatomical sites. All EPTB patients were started anti-TB therapy without definitive microbiology results. This indicates the diagnostic challenge of EPTB faced in our setting and proves to be significant for TB control in Ethiopia.

Diagnostic accuracy of Xpert MTB/RIF assay and non-molecular methods for the diagnosis of tuberculosis lymphadenitis

Background

Tuberculous lymphadenitis (TBLN) diagnosis remains a challenge in resource limited countries like Ethiopia. Most diagnostic centers in Ethiopia use smear microscopy, but it has low sensitivity in detecting tubercle bacilli in fine needle aspiration (FNA) specimens. FNA cytology (FNAC) is another widely applicable diagnostic option but it has low specificity for diagnosing TBLN. In 2014, WHO recommended Xpert MTB/RIF assay to be used in detecting TB from FNA specimen by considering the diagnostic limitations of microscopy and cytology. In Ethiopia, there is limited data on Xpert MTB/RIF performance in detecting TBLN from FNA. Therefore, this study aimed to evaluate the diagnostic performance of Xpert MTB/RIF assay and non-molecular methods (cytology, microscopy and culture) for the diagnosis of TBLN.

Methods

A cross-sectional study was conducted on 152 presumptive TBLN patients at St. Paul’s Hospital Millennium Medical College (SPHMMC) from December 2015 to May 2016 in Addis Ababa, Ethiopia. FNA specimens were collected from each patient. Individual patient specimens were examined by microscopy (acid fast and auramine O staining), cytology, Xpert MTB/RIF and culture. Each specimen was directly inoculated and its sediment following decontamination procedure onto two duplicate Löwenstein-Jensen (LJ) media. Composite culture (specimen positive by direct or concentrated or both culturing methods) and composite method (positive by either one of the non-molecular methods) were taken as reference methods. The data was captured and analyzed using software packages SPSS version 20 (SPSS Inc, Chicago, Illinois, USA). Sensitivity, specificity, positive predictive value, and negative predictive value were calculated.

Result

A total of 152 presumptive TBLN patients were enrolled in this study. Of these, 105(69%), 68(44.7%), 64(42%), 48(32%) and 33(22%) were positive for M. tuberculosis using composite method (positive by either one of the non-molecular method), composite culture, direct, and concentrated culture, respectively. TB positivity rate was 67.8%, 49.3%, 24.3%, and 14.5% using cytology, Xpert MTB/RIF, Auramine O (FM) microscopy, and Ziehl Nelson (ZN) microscopy, respectively. Using composite culture as reference, the sensitivity and specificity of Xpert MTB/RIF was 78% (95% CI: 73.7% to 82.3%) and 74% (95%CI: 69.4% to 78.6%), respectively. However, the sensitivity of Xpert MTB/RF improved from 78% to 92% using composite method as a reference. The high positivity rate observed in purulent (70%) followed by caseous (66.7%) type of aspirates by Xpert MTB/RIF.

Conclusion

Xpert MTB/RIF assay has both considerable sensitivity and specificity; it may be employed for better diagnosis, management and treatment of presumptive TBLN patients.

Granulomatous inflammation diagnosed by fine-needle aspiration biopsy

INTRODUCTION

Fine-needle aspiration biopsy (FNAB) is a minimally invasive biopsy technique and an important tool for diagnosing infectious diseases. Rapid onsite evaluation allows for triage for ancillary testing, including microbiologic cultures. We aimed to determine the etiology of granulomatous inflammation diagnosed by FNAB by correlating with culture results and clinical history.

MATERIALS AND METHODS

A 16-year retrospective review of cases diagnosed as "granulomatous inflammation" or "granuloma" was performed at the Departments of Pathology at the Zuckerberg San Francisco General Hospital and Trauma Center and University of California, San Francisco.

RESULTS

A total of 339 FNABs diagnosed as granulomatous inflammation were identified. Necrotizing granulomatous inflammation was present in 117 of 339 cases (34.5%) and non-necrotizing granulomatous inflammation was present in 222 of 339 cases (65.5%). A pathogen was detected in 100 of 339 (29.5%) FNABs by either cytomorphology, special stains, or culture, or a combination of more than one test. Of the 100 pathogen-positive cases, necrotizing granulomatous inflammation was seen in 50 of 100 (50%) and non-necrotizing granulomatous inflammation was identified in 50 of 100 (50%) cases. Culture results were available in 239 cases and positive in 70 (29%). Positive culture results included 40 of 239 (17%) cases with Mycobacterium tuberculosis complex, 15 of 239 (6.3%) with atypical mycobacterial species, 6 of 239 (3%) with Coccidioides immitis, 2 of 239 (<1%) with Histoplasma capsulatum, and 2 of 239 with Talaromyces marneffei (<1%).

CONCLUSIONS

Granulomatous inflammation is a nonspecific finding and suggests a broad range of disease processes, ranging from infection to malignancy. FNAB is an excellent minimally invasive technique that allows for ancillary testing critical for definitive diagnosis.

Epidemiology of tuberculous lymphadenitis in Africa: A systematic review and meta-analysis

INTRODUCTION

Tuberculous lymphadenitis is the most frequent form of extra-pulmonary TB (EPTB) and accounts for a considerable proportion of all EPTB cases. We conducted a systematic review of articles that described the epidemiological features of TBLN in Africa.

METHODS

Any article that characterized TBLN cases with respect to demographic, exposure and clinical features were included. Article search was restricted to African countries and those published in English language irrespective of publication year. The articles were retrieved from the electronic database of PubMed, Scopus, Cochrane library and Lens.org. Random effect pooled prevalence with 95% CI was computed based on Dersimonian and Laird method. To stabilize the variance, Freeman-Tukey double arcsine root transformation was done. The data were analyzed using Stata 14.

RESULTS

Of the total 833 articles retrieved, twenty-eight articles from 12 African countries fulfilled the eligibility criteria. A total of 6746 TBLN cases were identified. The majority of the cases, 4762 (70.6%) were from Ethiopia. Over 77% and 88% of identified TBLN were cervical in type and naïve to TB drugs. Among the total number of TBLN cases, 53% were female, 68% were in the age range of 15-44 years, 52% had a history of livestock exposure, 46% had a history of consuming raw milk/meat and 24% had history of BCG vaccination. The proportion of TBLN/HIV co-infection was much lower in Ethiopia (21%) than in other African countries (73%) and the overall African estimate (52%). Fever was recorded in 45%, night sweating in 55%, weight loss in 62% and cough for longer than two weeks in 32% of the TBLN cases.

CONCLUSIONS

TBLN was more common in females than in males. The high prevalence of TBLN in Ethiopia did not show directional correlation with HIV. Population based prospective studies are warranted to better define the risk factors of TBLN in Africa.

Fine needle non-aspiration cytology for the diagnosis of cervical lymph node tuberculosis: a single center experience

Introduction

The fine-needle cytology is being used as a first line of investigation in the diagnosis of head and neck swellings, as it is simple, cost effective and less invasive as compared to biopsy.

Objective

The aims of this study were to evaluate the results of the fine-needle non-aspiration cytology of cervical lymphadenopathy and to study the factors influencing the rate of non-diagnosis results.

Methods

This retrospective study was conducted on selected patients with cervical lymphadenopathy that had undergone a fine-needle non-aspiration cytology followed by a histological biopsy. The sensitivity, specificity, positive predictive value and negative predictive value of fine-needle non-aspiration cytology for diagnosing tuberculosis were estimated. The risk factors of non-diagnosis results were evaluated.

Results

The sensitivity, specificity, positive predictive value rates of fine-needle non-aspiration cytology for tuberculosis were 83.3%, 83.3%, 78.9% and 86.9% respectively. In total, 47 out of the 131 samples (35.8%) were considered non-diagnosis. Of the non-diagnosis samples, 84.2% (38 out of 47) were benign mostly due to tuberculosis (30 cases). Among the studied factors, only tuberculosis (confirmed by histopathological examination) was significantly associated with non-diagnosis cytology (p = 0.02, Odds-Ratio = 2.35).

Conclusion

Tuberculosis is currently the commonest cause of cervical lymphadenopathy in North Africa. Fine-needle non-aspiration cytology is safe and accurate in the diagnosis of cervical tuberculous lymph node that is associated with the risk of non-diagnosis cytology.

Empirical treatment with non-anti-tuberculosis antibiotics decreased microbiological detection in cervical tuberculous lymphadenitis

Diagnosis of cervical tuberculous lymphadenitis (CTL), the most commonly occurring form of extrapulmonary tuberculosis, remains as a challenge in clinic. Detection of the presence of Mycobacterium tuberculosis (Mtb) in fine needle aspiration cytology (FNAC) samples is one golden criterion to confirm the CTL diagnosis. Due to the non-specific clinical presentation, CTL might be confused with other lymph node enlargement diseases; therefore empirical treatment with non-anti-TB antibiotics is often initially administered. However, it is still unclear whether this diagnostic antibiotic treatment affects the positivity of Mtb detection in FNAC. The demographics and clinical characteristics of 732 lymph node enlargement patients who had underwent FNAC were retrospectively analyzed and 605 (82.65%) of them were diagnosed as CTL. A total of 279 CTL cases (279/605, 46.11%) with completion of three Mtb tests (AFB, NAAT, and Mtb culture) in FNAC samples were selected for analyzing the effect of empirical antibiotic treatment on the positivity of Mtb tests. Compared to CTL patients without antibiotic treatment prior to FNAC, patients received empirical non anti-TB treatment had significantly lower positivity for acid fast bacilli staining (adjusted OR 0.11, 95% CI 0.06-0.21), nucleic acid amplification test (NAAT) (adjusted OR 0.38, 95% CI 0.21-0.71), and Mtb culture (adjusted OR 0.11, 95% CI 0.06-0.19). In conclusion, this study demonstrated that empirical non anti-TB antibiotic treatment reduced the opportunity to confirm CTL by microbiological analysis. Patients with cervical lymph node enlargement should undergo FNAC for Mtb tests prior to initiation of empirical non anti-TB treatment.

Cervical tuberculous lymphadenitis: diagnosis and demographics, a five-year case series in the UK

Introduction Cervical tuberculous lymphadenitis is a low-volume condition in the UK with a potential for delayed diagnosis. This study describes typical demographic and clinical features of patients diagnosed with cervical tuberculous lymphadenitis in a UK population. The utility of cytological, histological and microbiological investigations is reviewed with comparison between fine-needle aspiration and open biopsy. This information can facilitate recognition of new cases and guide initial management. Methods Patients diagnosed with cervical tuberculous lymphadenitis between January 2009 and December 2013 at two district general hospitals were identified from local infectious disease databases. Retrospective case-note review was undertaken to collect demographic and diagnostic data and associated complications. Results Full data were available for 51 patients aged 19-70 years (mean 32.4 years) with mean follow-up of 370 days; 49/51 patients were immigrants to the UK with a wide geographic spread in the countries of origin and time since arrival; 42/51 had no significant comorbidities, although two patients had coexistent HIV infection. The clinical presentation was most frequently without constitutional symptoms (39/51) and often with no history of tuberculosis contact. Posterior triangle neck nodes were most commonly involved (26/51). Conclusion The 'typical' patient with cervical tuberculous lymphadenitis in our region is a young healthy individual who came to the UK from a high-risk country several years earlier. Diagnosis by fine-needle aspiration is as effective as open biopsy if fluid/pus is aspirated. Open biopsy is potentially associated with complications but does not appear to increase chronic wound discharge rates in our series.

Diagnostic performance of fluorescent light-emitting diode microscopy for tuberculous lymphadenitis in a high-burden setting

OBJECTIVE

Diagnosis of tuberculous lymphadenitis using fine-needle aspiration cytology is a simple and safe but low-specificity method, whereas conventional smear microscopy has variable sensitivity due to low bacterial load. We evaluated the diagnostic performance of fluorescent light-emitting diode (LED) microscopy on routinely collected fine-needle aspirates from tuberculous lymphadenitis presumptive cases.

METHODS

Fine-needle aspirates were collected from patients clinically suspected of having tuberculous lymphadenitis as part of routine diagnosis. Smear preparation was performed from the aspirate and processed for cytology, conventional Ziehl-Neelsen and LED microscopy. The remaining aspirate was processed for culture on Lowenstein-Jensen media. Capilia TB-Neo test was used to differentiate M. tuberculosis complex from non-tuberculous mycobacteria.

RESULT

A total of 144 tuberculous lymphadenitis presumptive cases were included. 66.7% (96/144) were positive for M. tuberculosis complex on culture. Only one isolate was identified as non-tuberculous mycobacteria. The detection rates of Ziehl-Neelsen and LED microscopy were 18.8% (27/144) and 34% (49/144), respectively. As compared to culture, sensitivity was 25.0% [95% CI: 16.3-33.7] for Ziehl-Neelsen microscopy and 45.8% [95% CI: 35.9-55.8] for LED microscopy. The specificity was 93.8% [95% CI: 86.9-100] for Ziehl-Neelsen microscopy and 89.6% [95% CI: 80.9-98.2] for LED microscopy. LED microscopy showed a statistically significant increase in sensitivity and similar specificity compared to Ziehl-Neelsen microscopy. Mean reading time of positive slides was 2.62 min/slide for Ziehl-Neelsen and 1.60 min/slide for LED microscopy. Cytology showed sensitivity of 82.3% and specificity of 54.2%. LED microscopy detected TB bacilli in 33.3% of cases cytologically classified as suppurative abscess.

CONCLUSION

The LED microscopy for tuberculous lymphadenitis had significantly higher sensitivity and shorter screening time than Ziehl-Neelsen microscopy. Use of LED microscopy among cases classified as suppurative abscess on fine-needle aspirate cytology improves evidence-based diagnosis of presumptive tuberculous lymphadenitis cases. Moreover, LED microscopy could be considered as an alternative approach in settings where fine-needle aspirate cytology is impractical.